1. Field of the Invention
This invention relates to a locking support arrangement for supporting a flexible sound-generating diaphragm and, more particularly, to a locking arrangement for clamping the diaphragm in position and preventing inadvertent disassembly.
2. Description of Prior Art
Piezoelectric transducers driven by a small disk of piezoceramic material bonded to a thin metal diaphragm are well known. When an appropriate electrical signal is applied to the disk, the disk changes its diameter, causing the composite structure of the piezoceramic disk and the metal diaphragm to flex accordingly from a flat shape into either a convex or concave shape. As the polarity of the electrical input signal changes, the shape of the flexible diaphragm also changes. By varying the polarity of the input signal at a particular frequency, the flexible diaphragm can be made to vibrate at the same frequency. To produce sound, some portion of the flexible diaphragm must be mounted to a fixed surface. This is typically accomplished by securing the diaphragm to an annular support surface by means of clamping or gluing. For loud sound, it is common to mount the diaphragm on a node ring of the diaphragm for the particular exciting frequency. The prior art mounting arrangements typically require careful alignment of the diaphragm and the support elements in order to assure that the diaphragm is secured on the desired node ring. In many instances the diaphragm is attached to the support member by a rubber-like cement which requires a period of time for curing.
By co-pending application Ser. No. 94,965 filed Nov. 16, 1979, now U.S. Pat. No. 4,302,695 in the names of Robert L. Boyles and Samuel Polonsky for "Support Arrangement for a Flexible Sound Generating Diaphragm" and assigned to the same assignee as this invention, an improved mounting arrangement for piezoelectric transducer-driven diaphragms is disclosed. The mounting arrangement taught therein comprises a substantially rigid support member and a clamping spider having annular means thereon for positioning and clamping a diaphragm between the rigid support member and the clamping spider on a node circle of vibration. The support members and the clamping spider are snapped together to rapidly and accurately provide the diaphragm mounting on the desired node ring. The clamping force is provided by resilient leg portions which extend from the spider into axial clamping engagement with the rigid support member. Assembly occurs due to radial camming action between the leg portions and the support member as the members are forced together axially. While this approach has been very effective, it is desirable that assurance be provided that the leg portions will not eventually release their hold on the support member.